High-protein food product and process for making

ABSTRACT

A dairy-based yogurt product having a protein level above 15%, sometimes more than 25%, with a smooth and rich texture and no grittiness. The yogurt product includes a particular selection of dairy proteins and other ingredients to raise the gelation temperature of the dairy proteins and avoid causing gelation or precipitation during pasteurization. Additionally, pasteurization temperatures, times and methods are selected to avoid gelation. Starting dairy proteins generally have relatively higher pH levels and low total acidity (TA) levels to help reduce gelation during pasteurization. Ingredients such as buffering agents and sequestering agents may be utilized to help raise the gelation temperature, as well as higher sugar levels which can control hydration of the proteins.

RELATED APPLICATION INFORMATION

This patent claims priority to U.S. application Ser. No. 14/699,433,filed Apr. 29, 2015, now U.S. Pat. No. 9,167,826, titled PROCESS FORMAKING HIGH-PROTEIN DAIRY PRODUCT, which is a continuation of U.S.patent application Ser. No. 14/270,536, filed May 6, 2014, now U.S. Pat.No. 9,040,107, titled METHOD FOR MAKING A HIGH-PROTEIN DAIRY PRODUCT,which claims priority from Provisional Patent Application No.61/897,086, filed Oct. 29, 2013, titled FROZEN, READY TO EAT FOOD.

NOTICE OF COPYRIGHTS AND TRADE DRESS

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. This patent document may showand/or describe matter which is or may become trade dress of the owner.The copyright and trade dress owner has no objection to the facsimilereproduction by anyone of the patent disclosure as it appears in thePatent and Trademark Office patent files or records, but otherwisereserves all copyright and trade dress rights whatsoever.

BACKGROUND OF THE INVENTION

The recent popularity and market demand of high-protein foods haveencouraged many companies to develop and launch a wide range of productsto address this consumer need. When developing dairy-based dessertproducts, however, formulators encounter rheological and texturallimitations during processing that have restricted them from reachingprotein levels above 15%. Most attempts fail due to the nature of dairyproteins to gel or precipitate in high moisture systems such as ready toeat desserts or beverages, especially under the high heat conditionsassociated with the required pasteurization step. In the case of dairyproteins that display resistance to thermal gelling or precipitation,the typical result is a product that sets up like silly putty in agelled matrix or precipitates and forms an unpleasant sandy or grittytexture. In either case, the products receive poor consumer acceptanceand are usually abandoned before they reach the marketplace.

There is thus a need for high-protein yogurt product that has a smoothand rich texture for a pleasant mouth feel.

SUMMARY OF THE INVENTION

The present application describes dairy-based yogurt products andprocesses for making having protein levels above 15%, sometimes morethan 25%, and that have a smooth and rich texture and no grittiness.Careful selection of dairy proteins raises the gelation temperature toavoid causing gelation or precipitation during pasteurization. Thestarting dairy proteins generally have relatively higher pH levels andlow total acidity (TA) levels. Ingredients such as buffering agents andsequestering agents may be utilized to help raise the gelationtemperature. Sugars can be used to control hydration of the proteins andtherefore also inhibit the tendency of high level diary proteins to gelat higher temperatures. Additionally, pasteurization temperatures, timesand methods are selected to avoid gelation or precipitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of an exemplary process for producing thehigh-protein yogurt;

FIG. 2 is a flowchart showing a preferred process for producing aculture batch to subsequently be combined with a high-protein dairy basemix;

FIG. 3 is a table listing preferred ingredients and their properties forforming an exemplary culture batch;

FIG. 4 is a flowchart of an exemplary process for producing ahigh-protein dairy base mix for vanilla yogurt to be combined with theculture batch;

FIG. 5 is a table listing preferred ingredients and their properties forforming an exemplary high-protein dairy base mix;

FIG. 6 is a table listing preferred proportions of ingredients in anexemplary final mix including the culture batch and base mix along withflavoring ingredients to produce vanilla yogurt;

FIG. 7 is a table listing the total separate ingredients and theirproperties for an exemplary formulation of vanilla yogurt;

FIG. 8A is a table listing preferred ingredients and their propertiesfor forming an exemplary high-protein dairy base mix specifically forchocolate yogurt;

FIG. 8B is a table listing preferred proportions of ingredients in anexemplary final mix to produce chocolate yogurt;

FIG. 9 is a table listing preferred proportions of ingredients in anexemplary final mix to produce banana yogurt;

FIG. 10 is a table listing preferred proportions of ingredients in anexemplary final mix to produce blueberry-pomegranate yogurt; and

FIG. 11 is a flowchart of a number of preliminary and finishing stepsthat are typically performed when producing the exemplary high-proteinyogurt.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present application discloses methods for preparing high protein(>15%) ready to eat food products, including frozen yogurts, thatprovide a rich and creamy texture with high consumer appeal. The methodsdescribed herein are particularly effective in incorporating dairyproteins into such food products without resulting in a gritty or siltytexture. Many desirable dairy proteins tend to gel upon heating, such asduring pasteurization, and the methods described herein are believed tobe the first to successfully utilize high-protein dairy proteins withoutcausing gelation or precipitation. Precipitation causes a gritty orsandy texture while gelation forms a rubbery silly putty texture.

Of course, it should be understood that certain aspects of the methodsdescribed herein could be utilized with other proteins to produce foodproducts. For example, proteins derived from canola, soy, bean, pea, andeven hemp have been used in food products. However, regulatory bodiessuch as the FDA in the U.S. typically set minimum standards for dairyproteins in food products that are classed as dairy products, such asyogurt. Therefore, in the context of the present application the term“yogurt” is that food product which meets FDA standards for yogurt. Morespecifically, before the addition of bulky flavors, yogurt must containnot less than 3.25% milkfat and not less than 8.25% milk solids not fat.(21 U.S.C. §131.200) Lowfat yogurt, before the addition of bulkyflavors, must contain not less than 0.5% nor more than 2% milkfat andnot less than 8.25% milk solids not fat. (21 U.S.C. §131.203) And nonfatyogurt, before the addition of bulky flavors, contains less than 0.5%milkfat and not less than 8.25% milk solids not fat. (21 U.S.C.§131.206) These minimum levels of dairy solids are easily processed butwhen the dairy protein levels go higher, e.g., exceeding 15%, such as inhigh protein dairy products, it becomes more challenging to keep theseproteins from gelling or precipitating during the pasteurizationprocess.

For example, frozen yogurt that uses a combination of both a culturedcomponent and a dairy base component is one of the most difficult dairydesert products to make into a high protein product because the culturecomponent must be lower in solids for the cultures to grow. This meansthat the dairy base must have a correspondingly higher protein contentto make up for the lower level in the culture. The present processes arealso useful in producing high protein ice cream or dairy desserts.

The following components constitute choices that can be assembled asneeded to create a method that can achieve the desired finished producttexture while exceeding the 15% protein level. In terms of definition, aproduct or precursor to the product is “high-protein” if it has aprotein level of at least 15%. As the desired protein target levelincreases above 15%, it is necessary to employ novel component andprocessing choices to obtain a rich, appealing texture. By employing asuitable combination of the different choices described below, one cancreate texturally rich products with significantly higher proteinlevels. Testing of these methods has shown that levels in excess of 25%protein can be formulated while still delivering finished food products,e.g., a snack or dessert, with a rich and appealing texture.

The following principles may be utilized in varying degrees andcombinations to result in the desirable dairy products described herein:

1. Selecting proteins that have higher gelation temperatures, yet do notexhibit a gritty texture. Whey protein concentrates or isolates thathave pH' s above 6.5 and lower TA levels tend to provide the bestresistance to heat gelation.

2. Utilizing a suitable combination of proteins. For instance, a smallamount of a protein with a higher gelation temperature that has lessthan ideal texture, such as ones with a slightly “silty” (powdery)texture, with proteins that have a highly desirable texture. Our testshave shown that in some cases these combinations can act synergisticallyto raise the gelation temperature above the level of the lower gelationtemperature protein while still providing a rich texture.

3a. Utilizing sequestering agents such as phosphates like sodiumhexametaphosphate or other sequestrants like trisodium citrate that cancomplex calcium (sometimes termed chelation) and minimize gellingmechanisms such as calcium bridging of proteins.

3b. Utilizing buffering agents such as trisodium citrate or phosphateslike disodium phosphate or sodium tripolyphosphate can also help toreduce gelation of milk proteins caused by lower pH.

4. Inhibiting complete hydration of the protein by binding the waterwith ingredients such as sugars, sugar alcohols, glycerine, etc., thathave a significantly higher water binding energy or affinity than theprotein. Sugars like fructose or dextrose work especially well.

5. Reducing the necessary processing pasteurization temperatures byextending the pasteurization time; for example, by using vatpasteurization.

6. Splitting up the formulation into two or more steps that arepasteurized separately.

7. Use of phospholipids or phosphorylated proteins or peptides act toraise the thermal gelation temperature of several proteins tested andalso softened the resultant gel when it did form.

Each of these steps can be optimized to take advantage of the methodslisted herein. The applicants have found that these principles areparticularly effective when making high protein fermented frozenyogurts, especially those with more than 20% protein.

FIG. 1 is a flowchart of an exemplary process for producing thehigh-protein yogurt. First of all, the ingredients are acquired, storedand appropriately refrigerated. In a preferred embodiment, all of theingredients are natural, GMO-free, and RBST-free for marketing to awider range of consumers. Organic starting ingredients are alsopreferred.

The production process initially takes two tracks: preparation of aculture batch as described in more detail below with regard to FIG. 2,and preparation of a high-protein base mix as described in more detailwith regard to FIG. 4. Both the culture batch and the high-protein basemix are pasteurized and cooled to the same temperature, preferablyaround 38-39° F., and then mixed in a flavor tank. Additional flavoringredients are then added to the flavor tank, and a number of ancillarysteps performed to prepare the product for distribution. As explainedabove, the methods described herein are useful for preparinghigh-protein food products in general, although the illustrated stepsare especially suited for preparing high-protein yogurts.

FIG. 2 illustrates an exemplary process for producing a culture batch tosubsequently be combined with the high-protein dairy base mix. Theingredients of an exemplary culture batch for use in the production of ahigh-protein vanilla yogurt are given in FIG. 3. Specifically, asidefrom the culture itself, the dry ingredients include skim milk powder,dextrose, de-oiled sunflower lecithin, a whey protein concentrate, awhey protein isolate, and trisodium citrate. The culture specified inFIG. 3. is ABY-2C, from Danisco, which is a readily available productand has been on the market for over ten years. In that time itsformulation has not changed. Its specified use is 0.03 g per liter. ABY2C is a blend of individually selected and freeze-dried strains ofulactic acid bacterial cultures and lactose whose composition isBifidobacterium lactis, Lactobacillus acidophilus, Lactobacillusdelbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis,and Streptococcus thermophilus. FIG. 3 specifies 57.0 grams of thisculture per 500 gallons. Chemical analysis of the ABY-2C cultureindicates a total level of probiotic cultures in the inoculum of approx.200 Billion/gram with an approximate split of the individual cultures asfollows: 30% Bifidobacterium lactis; 5% Lactobacillus acidophilus; 25%Lactobacillus delbrueckii subsp. Bulgaricus; 5% Lactobacillusdelbrueckii subsp. Lactis; and 35% Streptococcus thermophiles.

In a first step, the dry ingredients except the yogurt culture are mixedwith water in a high shear liquiverter. High shear mixing conditions maybe created using numerous commercial mixing systems, for example,Likwifier, Liquiverter, etc. These mixing conditions may be exemplifiedby, but are not limited to, a pitch blade turbine operated with animpeller velocity of at least about 1000 ft/min. (900 rpm, 2.54 inchimpeller) for a 650 ml batch in a 1.25 liter vessel. Other high shearmixers, mixer blade configurations, high shear roto-stator devices,etc., with a shear rate of least about 45,000 sec⁻¹ may also beemployed. For instance, a recirculating tri-clover powder horn systemworks as well.

The initial ingredients are mixed until lump free and uniform. Next, thetechnician measures and adjusts the percentage of solids in the mix; thetarget being between 14-16%, with a preferred target of 15.03±0.4%.Next, the ingredients are pasteurized and transferred to a culture tankwhere the temperature is adjusted to about 110°±1° F. Pasteurizationdesirably occurs in a water-jacketed pasteurization vat or via ahigh-temperature short-time (HTST) system at a minimum temperature ofabout 177° F. The pasteurized ingredients are then gently agitated andthe culture added (inoculation) to the top thereof following directionsprovided by the culture manufacturer. Agitation is continued for a shortperiod, for example 15 minutes, to evenly disperse the culture throughthe mix. Prior to the next step, agitation is halted while thetemperature is maintained at about 110°±1° F.

Over a period of time, such as 5 hours, the technician then periodicallymeasures the total acidity (TA) and pH of the culture batch. Totalacidity (TA) is measured by a titration method, where the concentrationof acid in a liquid is determined by slowly adding a small amount of abase until a change in color occurs due to the presence of an addedindicator. For example, the TA and pH are measured at the beginning andat every hour to establish a curve for both parameters over time. Theprocess continues until desired measures of TA and pH are reached.

The target pH is acidic, below 7, preferably less than about 6.5, and inone exemplary embodiment the process continues until the pH is about4.9±0.05. An acidic pH slows culture growth, and the acids generated bythe desirable culture tend to inhibit growth of potential contaminatingmicro-organisms. As the culture ferments, the proteins open up andprovide additional stability and viscosity to the culture. Consequently,the addition of stabilizers such as gums and emulsifiers is notrequired. At the same time, the target TA is less than 1.5, and morepreferably the target TA is about 1.0±0.1.

After hitting the pH and TA targets, the technician starts agitating theculture batch and cools the batch down to about 38-39° F. This “breaks”the culture at the target parameters, or in other words stops the growthof the culture and the production of additional acid. At this point, theculture batch is ready to be combined with the high-protein base mix,which will be described below.

The flowchart of FIG. 4 illustrates an exemplary process for producingthe high-protein dairy base mix for vanilla yogurt to be combined withthe culture batch, while FIG. 5 lists preferred ingredients and theirproperties for forming the base mix. The main ingredients of the basemix are water, a whey protein concentrate, skim milk powder andsweeteners including cane sugar, inulin and dextrose. Inulins are agroup of naturally occurring polysaccharides that function as aprebiotic fiber and are produced by many types of plants, most oftenextracted from chicory. Less prevalent in the base mix is heavy cream, awhey protein isolate and Stevia extract.

Several ingredients in the base mix are included to reduce thepropensity of the proteins in the mix to gel. In particular, the basemix preferably includes one or more buffering and/or sequestering agentsthat essentially increase the gelation temperature of whey proteins. Forinstance, the process desirably includes a sequestering agent such assodium hexametaphosphate or trisodium citrate, which complexes calciumand minimizes its potential to react with proteins which can causegelation. It should be noted that natural ingredients such as trisodiumcitrate are preferred by the targeted consumer group. Likewise, abuffering agent such as trisodium citrate or sodium tri-polyphosphatecan help stabilize pH when acid levels increase which also reduces thepropensity for protein gelation or precipitation. In this way, a proteinmay be used that would normally gel at the temperatures used forpasteurization, and would otherwise produce an unsatisfactory texture inthe yogurt (at the extreme, like the texture of silly putty if gelled ora coarse sand if precipitated). It should be noted that sugars such assucrose and dextrose will bind with water and thus retard proteinhydration which also reduces its ability to gel. However, for dietaryreasons the amount of cane sugar may be limited in the exemplaryformulation (8.5% by weight of the base mix in FIG. 5) and its sweetnessreplaced by the addition of another sweetener such as Stevia.Additionally, the amount of cane sugar in the overall dairy food productis reduced by mixing with the lower sugar containing culture (e.g., thesugar may be limited to no more than 7.5% by weight, such as in FIG. 7which shows an example of 7.310%).

Furthermore, a particular dairy protein that starts out with relativelyhigh gelation temperatures as well as smooth textures may be combinedwith a small amount of another dairy protein that has even highergelation temperatures but a somewhat less than smooth texture to furtherretard gelation. For example, the exemplary base mix ingredientsprovided in FIG. 5 includes a whey protein concentrate with a desirabletexture in a 50:1 ratio by weight to a whey protein isolate with a lessdesirable texture. In a preferred embodiment, proteins which have astarting pH of greater than 6.5 and the total acidity (TA) of less than0.3 are used, preferably less than 0.25, and perhaps down as low as0.20-0.22. Exemplary proteins may be mixed with de-ionized water at a10% protein level and tested for these properties, and variouscombinations of proteins can also be heat tested to find a desirablesynergistic match.

With reference again to FIG. 5, the process for making the base mixagain begins by proper acquisition, storage, and refrigeration of theingredients. Prior to mixing most of the ingredients together, thetechnician will premix Stevia with one of the “minor” dry ingredients(e.g., inulin) to facilitate dispersal throughout the final mix. Next,each of the ingredients is added to cold or warm water in proper orderin a high shear mixer, recirculating liquiverter, or powder horndispersal system. The ingredients are agitated for a short period (e.g.,10 minutes) until the mix is lump free and uniform, and the dryingredients are hydrated.

Next, the technician measures and adjusts the solids of the mix to atarget of between 30-60%, with a preferred target in our example of43.75±1.0%. The adjusted mix is then pasteurized in a water-jacketedpasteurization vat at a minimum temperature of about 155° F. for aperiod of no less than 30 minutes. As with the culture batch, an HTSTsystem may also be used, but an ultrahigh temperature (UHT)pasteurization technique should not be used so as not to unduly increasethe temperature and cause gelation. Homogenization should not be part ofthe process. Finally, after pasteurization the mix is cooled down toabout 35-39° F., more preferably 38-39° F., and left for about an hourto de-aerate. The base mix is then ready for combining with the culturebatch, as was described above with respect to FIG. 1.

FIG. 6 is a table listing preferred proportions of ingredients in anexemplary final mix including the culture batch and base mix along withflavoring ingredients to produce vanilla yogurt. In the exemplaryformulation, 86% by weight of the finished mix is the base mix, whileabout 13.6% is the culture batch, with the rest of the ingredientscomprising vanilla flavoring as shown. The finished mix is agitated forat least 10 minutes minimum to assure even distribution of the flavoringingredients. Measurement of the product solids and density should bedone for quality control. In this example, the targeted finished productdensity is 0.888 g/ml with a range of ±0.042 g's/ml. This is equivalentto 26.26 g/fl. oz. (±1.25 g's/fl. oz.), 210.1 g/cup, or 7.41 lbs/gallon.

FIG. 7 lists the total separate ingredients and their properties for thevanilla yogurt formed in the process using the ingredients of FIGS. 3,5, and 6. As is apparent, the largest ingredients by weight are water,the whey protein concentrate, the culture batch, and various sweeteners.The final protein level is around 20%, and the level of total solids(TS) is around 40%.

FIG. 8A lists preferred ingredients and their proportions for forming ahigh-protein dairy base mix specifically for chocolate yogurt, whileFIG. 8B shows the preferred proportions of ingredients in an exemplaryfinal mix to produce the chocolate yogurt. The formula is much like thatfor vanilla, but cocoa powder is added to the base mix. Further, vanillabean specks are not added to the final mix.

FIG. 9 is a table listing preferred proportions of ingredients in anexemplary final mix to produce banana yogurt. In this formulation,vanilla bean specks are still added as well as banana purée and bananaflavor of about 3% by weight.

FIG. 10 lists preferred proportions of ingredients in an exemplary finalmix to produce blueberry-pomegranate yogurt. Instead of vanilla beanspecks, a number of fruit additives are included as well as red beetconcentrate to provide deeper red color.

FIG. 11 is a flowchart of a number of preliminary and finishing stepsthat are typically performed when producing the exemplary high-proteinyogurt. Namely, the separate steps of receiving and storing the variousingredients are indicated toward the top of flowchart prior to mixing toform the culture batch and the high-protein base mix. Once the twocomponents have been properly mixed and cooled, they may be passedthrough an auger-type chiller which converts the flavored mix into afrozen yogurt. Optionally, fresh fruits or other ingredients may beadded at this point prior to filling and packing the product intocontainers. An additional requirement is to scan for bits of metal as aprecautionary quality control measure. Finally, the product is stored infreezers and ultimately distributed to the wholesale and retailestablishments.

Throughout this description, the embodiments and examples shown shouldbe considered as exemplars, rather than limitations on the apparatus andprocedures disclosed or claimed. Although many of the examples presentedherein involve specific combinations of method acts or system elements,it should be understood that those acts and those elements may becombined in other ways to accomplish the same objectives. With regard toflowcharts, additional and fewer steps may be taken, and the steps asshown may be combined or further refined to achieve the methodsdescribed herein. Acts, elements and features discussed only inconnection with one embodiment are not intended to be excluded from asimilar role in other embodiments.

What is claimed is:
 1. A food product comprising: a mixture having atotal protein content of at least 15% by weight and comprising apasteurized culture batch and a pasteurized base mix, wherein theprotein in the mixture is smooth, rich and not gritty; the culture batchcomprising a first protein dispersed and hydrated in liquid with atleast one ingredient that retards gelation or precipitation of the firstprotein at higher temperatures, and inoculated with a culture which hasgrown in the culture batch; and the base mix comprising a second proteindispersed and hydrated in liquid, the base mix further including atleast one dry ingredient that retards gelation of the second protein athigher temperatures.
 2. The food product of claim 1 wherein at least oneof the first protein and the second protein is selected from a groupconsisting of a protein isolate and a protein concentrate.
 3. The foodproduct of claim 1 wherein at least one of the first protein and thesecond protein is derived from canola, soy, bean, pea or hemp.
 4. Thefood product of claim 1 wherein at least one of the first protein andthe second protein has a pH of greater than 6.5 and a total acidity ofless than 0.3, wherein the first protein and the second protein haverespective gelation temperatures, and the gelation temperature of atleast one of the proteins is higher than the gelation temperature of theother.
 5. The food product of claim 1 wherein the first protein is thesame as the second protein.
 6. The food product of claim 5 wherein theprotein with the higher gelation temperature is a protein isolate, andthe other protein is a protein concentrate.
 7. The food product of claim1 wherein the culture batch includes a sequestering agent that complexeswith calcium.
 8. The food product of claim 1 wherein the culture batchincludes a buffering agent that minimizes pH fluctuations in the culturebatch.
 9. The food product of claim 1 wherein at least one of the dryingredients of the base mix is selected from the group consisting of asequestering agent that complexes with calcium and a buffering agentthat minimizes pH fluctuations in the base mix.
 10. A food productcomprising: a mixture having a total protein content of at least 15% byweight and comprising a pasteurized culture batch and a pasteurized basemix that are formed separately and blended together after formation; theculture batch comprising a first dairy protein dispersed and hydrated inliquid with at least one ingredient that retards gelation orprecipitation of the first dairy protein at higher temperatures, andinoculated with a culture which has grown in the culture batch preparedand pasteurized separately from the base mix; and the base mixcomprising a second dairy protein dispersed and hydrated in liquid, thebase mix further including at least one dry ingredient that retardsgelation of the second dairy protein at higher temperatures, the basemix prepared and pasteurized separately from the culture batch, but nothomogenized.
 11. The food product of claim 10 wherein the culture batchincludes either or both a sequestering agent and a buffering agent, andthe base mix includes either or both a sequestering agent and abuffering agent.
 12. The food product of claim 11 wherein both theculture batch and the base mix include a sequestering agent.
 13. Thefood product of claim 10 wherein the first protein includes a proteinisolate and a protein concentrate.
 14. The food product of claim 10wherein the first protein and the second protein have respectivegelation temperatures, and the gelation temperature of one of the twoproteins is higher than the gelation temperature of the other.
 15. Thefood product of claim 10 wherein at least one of first protein and thesecond protein has a total acidity of less than 0.25.
 16. The foodproduct of claim 10 wherein at least one of first protein and the secondprotein has a pH of greater than 6.5 and a total acidity of less than0.3.